The ATP-dependent DNA helicase RecQ () is involved in genome maintenance []. All homologues tested to date unwind paired DNA, translocating in a 3' to 5' direction and several have a preference for forked or 4-way DNA structures (e.g. Holliday junctions) or for G-quartet DNA. The yeast protein, Sgs1, is present in numerous foci that coincide with sites of de novosynthesis DNA, such as the replication fork, and protein levels peak during S-phase.A model has been proposed for Sgs1p action in the S-phase checkpoint response, both as a 'sensor' for damage during replication and a 'resolvase' for structures that arise atpaused forks, such as the four-way 'chickenfoot' structure. The action of Sgs1p may serve to maintain the proper amount and integrity of ss DNA that isnecessary for the binding of RPA (replication protein A, the eukaryotic ss DNA-binding protein)-DNA pol complexes. Sgs1p would thus function by detecting (or resolving) aberrant DNA structures, and would thuscontribute to the full activation of the DNA-dependent protein kinase, Mec1p and the effector kinase, Rad53p. Its ability to bind both the large subunit of RPA and theRecA-like protein Rad51p, place it in a unique position to resolve inappropriate fork structures that can occur when either the leading or lagging strandsynthesis is stalled. Thus, RecQ helicases integrate checkpoint activation and checkpoint response.

This database is part of a project that received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement number 649024).